The current practice in blister packages is to use a thermoformed front blister made from virgin material usually polyvinyl chloride (PVC) and a back made from SBS card stock, which is made from bleached wood fiber. This package does not use recycled materials and is virtually unrecyclable itself. There is no system in place that collects and separates the materials in the current package. Indeed, disposing of PVC may become even more problematic for the refuse and recycling authorities since incineration of PVC produces some hazardous byproducts such as HCL, dioxin and furon. The paperboard back of current blister packages while recyclable is not recovered because of the difficulty thereof, and the lack of systems to separate it from the PVC. The only safe disposal method for the current blister pack is the landfill.
In an attempt to relieve some of the burden on our landfills, degradable plastic containers have been suggested. These containers are made of a plastic resin which is designed to decompose when they are exposed to ultra-violet light, oxygen or temperature. U.S. patents that disclose this type of plastic resin include: U.S. Pat. Nos. 4,038,228; 4,025,580; 4,048,410; 4,056,499; 4,051,306; 4,056,665; 4,101,720; and 4,191,320. While all of these patents disclose degradable plastic resins used in packages, they do not solve the real problem of recycling these packages.
Recyclable materials have been incorporated into packages in the past, but most of these packages do not allow for the entire package to be recycled easily. For example, U.S. Pat. No. 4,022,206 (Hilleman et al.) discloses a package that has a triple layer material. The outer layer is a high density protective plastic such as polyethylene terephthalate, and is used to protect the bag from abrasions. The outer layer is bonded to a foil layer such as aluminum. The foil layer in turn is bonded to an inner layer of polyolefin material. While the elements of this bag are recyclable, the bag is designed in such a manner that recycling such a bag is not cost effective. Similarly, U.S. Pat. No. 3,921,805 (Compere); and U.S. Pat. No. 4,211,326 (Hein et al.) disclose the use of polythylene terephthalate in combination with other material.
Although polyethylene terephthalate (PET), PET-G or R-PET has been tried in blister packages before, it has never been designed into a package specifically to address the needs of disassembly and ease of recycling.